Tail skid for airplanes



Nov. 27, E928,

c. w. DW ORACK TAIL SKID FOR AIRPLANES Filed March 18, 1924 11v VEN OReffzarlas WDwaraw/fi a r flaw? .4 TTO NEY Patented Nov. 27, 1928..

UNETED arns CHARLES W. .DWORACK, OF DAYTON, OHIO.

TAIL SKID FOR AIRPLANES.

Application filed March 18, 1924. Serial No. 700,101.

This invention relates to tail skids for airplanes, and is generallyconcerned with the provision of a practical form of skid atford ing asupport for the tail which renders the operation of turning on theground less difficult so that manual assistance is uimecessary andwherein the worn portion of the skid may be renewed with minimum labor.

Witlr the above-stated object in mind the present invention provides atail skid bar pivoted in the fuselage, and having the usual shockabsorbing means restraining its pivotal movement at the time of impactwith the ground and having a pivoted skid shoe capable of a limitedamount of swinging movement on the free end of the bar, the latterhaving renewable wear ribs welded thereon so that the matter ofreplacing the same involves merely the removal of the shoe instead ofthe entire skid assembly.

In the accompanying drawin illustrating the invention, 7

. Fig. 1 is a View of the tail portion of an airplane fuselage showingmy improved tail skid. v v

' Fig. 2 is a bottom view of the skid shoe which is pivotally mounted onthe end of the skid bar.

Referring to. the drawing, the skid bar 10 is shown pivoted at 11 on abracket 12 in the tail end of the fuselage. The inner end of the bar 10has a U fitting 13 bolted at 14 which embraces a tube 15 rigidly mountedin parallel relation to the bar 10 in the fuselage. A shock absorbingcord 16 is Wound about the bar 10 and tube 15 above a flange 17 providedon the bar 10 so that the pivotal movement of the bar 10 at the momentof impact and while taxiing is yieldingly restrained. The U fitting 13limits the extent of movement of the bar 10 by coming into engagementwith the tube 15..

The outer end of the bar 10 is provided with a clevis 1'8 offset fromthe bar 10 to provide 5 a vertical pivot for the skid shoe 19. A bolt.20 passing through the clevis 18 secures the shoe 19 in position, andis preferably provided with a castellated nut 21 so that a cotter pin 22may be employed to insure against to the accidental loosening of thebolt. The bolt 20, it will be noted, is hollow and has a springpressedball closure 23 in the upper end whichyields upon, pressure of an oilcan spout to admit oil to the bore thereof. This lubrication insuresthefreedom of movementof the intact.

skid shoe 19 so that the plane may turn relatively freely on the ground,and no manual assistance is needed. It is apparent that the verticalpivoting of the shoe 19 onthe clevis of the bar 10, and the horizontalpivoting of the bar 10 in the fuselage provides a universal pivotmountso that the shoe swings sidewise to enable turning, and the bar 10pivots on a horizontal axis to compensate for unevenness of the groundwhere the plane is taxiing or to give at the moment of impact whenlanding. The shoe 19 has laterally extending lugs 24 to limit theswinging movement thereof. These lugs engage the sides of the clevis 18at the limits of movement of the shoe.

The skid shoe 19 is of.metal, preferably forged, and for lightness ismade hollow with a channel-shaped cross section. This also gives it themaximum strength to Withstand the shocks to which it is subjected intaxiing and in landing.- The underside of the shoe 19 has a longitudinalsledding rib 25 which maintains the proper tracking relation of the shoein taxiing. A cross rib 26 is provided near the trailing edge of theshoe which serves the purpose of braking the movement of the plane inlanding. Both ribs are suit-ably welded to the shoe, and when theybecome worn to a certain extent, it is contemplated to remove the shoeand trim off the unused portions of the ribs and replace the same withnew ribs. This operation is relatively simple and inexpensive. It wasformerly the practice toremove the tail skid as a unit from the plane,thereby necessitating upon replacement, new shock-absorbing cord. Thisin itself is expensive, and the labor expended further renders thismethod of operation impractical. In the present case, it is necessaryonly to remove the bolt 20 to remove the skid shoe 19 and the remainderof the tail skid assembly isleft I claim 1. In a tail skid forairplanes, a skid shoe having renewable ribs welded on the bottomsurface thereof, one being Welded longitudinally and another cross-wiseof the bottom surface. v

2. In a tail skid for airplanes, a skid shoe of metal to have renewableribs welded on the bottom surface thereof, said shoe being formed hollowfor lightness and being channel-shaped for strength.

In testimony whereof I aflix my signature.

CHARLES w. nwoaAoK.

